Deposition of tungsten in vapor phase from tungsten hexafluoride

Tungsten layers adherent to silicium are obtained by reducing tungsten hexafluoride at 500 to 700C. The interface layers exhibit a fair percentage of fluorine and silicon. A silicide at the interface would justify the low contact resistance measured. On the other hand, using a tungsten layer of a few microns as a barrier against penetration of the eutectic aluminum-silicon when allying a semiconductor to a solid tungsten electrode (power semiconductors) was tried out.